• Diagnosis
• Chlamydia Trachomatis
• Syndromic Management

Caveat emptor: the principle that a person who buys something is responsible for making sure that it is in good condition, works properly, etc (Merriam-Webster Dictionary. (http://www.merriam-webster.com)). Hurly et al1 provide an excellent, real-world evaluation of the performance of two point-of-care (POC) assays for detection of Chlamydia trachomatis which demonstrates the importance of this philosophy. The investigators describe performance, both sensitivity and specificity, for both assays that is substantially poorer than the estimates provided in the manufacturers’ package inserts.

The article by Hurly and colleagues serves as a much needed reminder that continual assessment of the true performance, outside clinical trial settings, of any diagnostic assay is necessary for a number of reasons. These include: (1) changes in assay performance (real and estimated) over time, (2) operating conditions that differ from clinical trial settings and (3) the potential impact of population-specific characteristics. It is clear that the estimations of assay performance are only as good as the quality of the available comparators at the time of clinical trials. Thus, for example, when enzyme immunoassay assays for chlamydia were evaluated against culture, the sensitivity estimates (80–91%)2 were substantially higher than when reassessed in comparison with nucleic …